My sister is a coeliac (cannot eat gluten). We went to Disney April-May last year and managed fine. We took some gluten-free food to the parks in case we couldn't find anything to eat but did not really need them.
We had read the information from AllEars (which Bob has posted above). For the most part at Counter-Service restaurants there was enough different stuff for there to be one or two options which were available to her. We found that Pizza Planet in Hollywood Studios do gluten-free pizzas on request (but they do take quite a long time to cook) which she was very pleased about.
The only Table Service meals we had there were at Kona Cafe and Jikos. Both were excellent. The chef (at Kona) and our server (at Jikos) walked through the menu and pointed out exactly what was and was not gluten-free. Where meals were not gluten-free, they offered to either change what it was served with or create special gluten-free versions (of sauces etc.). There were only two or three items from each restaurant which were totally off limits. In each case they did everything they could to help us, and (unlike most restaurants in the real world) the servers did actually seem to know what they were talking about. We were very impressed.
If you are making ADRs for table service, I suggest you mention when booking that you cannot eat gluten, and mention again when you check in, and again when you meet your server.
Before our last trip, we were a little anxious about being able to eat at Disney. Our next trip is in December 2009, and we are on the Deluxe Dining Plan - i.e. not worried at all.
